Seagrass resilience: Where and how to collect donor plants for the ecological restoration of eelgrass Zostera marina in Rongcheng Bay, Shandong Peninsula, China

Abstract

As seagrasses are not available with commercial nursery stocks, the removal of a large amount of plant materials may damage donor populations. We evaluated the recovery of the eelgrass Zostera marina following the removal of entire plant patches (0.01–0.49 m2) at the edge and interior of an eelgrass bed in Rongcheng Bay, Shandong Peninsula, China, through a field experiment. We investigated the shoot density, morphology and growth of recovering plants following excavation. We found that the removal of entire small patches with excavation areas ≤0.25 m2 in the interior of the eelgrass bed was the most suitable strategy for harvesting donor plants of Z. marina. Small patch excavation (≤ 0.25 m2) was able to promote asexual reproduction in recovering plants, and their shoot density and morphology equaled or exceeded those of natural plants <7 months after harvesting. These results indicate that Z. marina plants have a strong capacity for resilience from physical disturbance through rhizome elongation in the harvested area.